KC Gardens

Red Maples have beautiful foliage, but trunk issues make it a bad choice

Damage to a red maple
Damage to a red maple Submitted photo

From Dennis Patton:

Okay, I admit I have a personal bias against one of the most popular trees planted in the landscape these past 10 to 15 years. Nurserymen, landscapers and tree lovers have taken me to task for my strong dislike of this popular tree. I must admit though, after looking at a number of tree photos e-mailed to our gardening hotline at Johnson County Extension, I feel vindicated for my distain for this tree that most others love, red maple.

I’ll give you the fact that red maples have some of the most spectacular fall color of any tree we grow. But my dislike for this tree has nothing to do with fall color or its ability to withstand our clay soils. My objection to this tree is based solely on its trunk bark characteristics.

Red maples have very thin, light-colored bark. As a result they suffer from a number of trunk issues. I think if you even looked at one crossly it would split! Red maple bark, when damaged, results in cankers, splits, or cracks that weaken the vascular system and leads to rot and decay. As a result of the damage to the tree, the growth is slowed and decay sets in, which means at some point the tree will fail.

The problem is most people don’t know this dirty little secret about the red maple until the damage is done. That is when our office gets photo after photo of a trunk-injured red maple. They want to know what it is and what can be done. I must confess that they don’t like the answer. The simple, cruel truth is, in most cases, the best remedy is to turn the tree into firewood. Ouch, that hurt!

Here is the problem. We cut our skin. We put on a bandage, and in a matter of a few days our body has grown new skin and healed the wound. The problem is trees don’t heal, they seal. What I mean by that is, they seal off the injury, and that is not a quick fix. Often before the tree can seal off the injury with new bark, rot and decay is occurring which means the main trunk is weakened and valuable growth is lost.

As I stated earlier, prevention is the key. Baby the trunk when planting, and for the first 10 or so years of the tree life. Avoid damaging the trunk when transporting. Just a bump on the tailgate hauling the plant home from the nursery will lead to a dead spot. Lawn mower and weed whips damage a lot of bark. But the biggest issue is winter injury. The light gray-colored bark absorbs winter sunlight causing the cells in the cambium layer to rupture resulting in a long, vertical crack, usually on the south-southwest side. Once any damage occurs there is no way to “fix it.”

So how do you prevent damage? The simple answer is, don’t do anything to wound the trunk. Transport safely, mulch around the tree, and, this last recommendation is somewhat disputed, wrap the trunk during the winter months. Tree wraps should be applied to any light gray-colored trunk after leaf drop and removed in the spring. Tree wrap is not a guarantee but may help reduce the issue.

The goal of this column is twofold. First is to help you prevent your red maple from falling prey to this all too common problem. The second is to maybe help you think twice about planting more red or red maple crosses in the landscape. There are so many other great trees that deserve a chance to shine. Please, no hate mail about my bias against this tree. I realize I am sticking my neck out, but someone has to take a stand.

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